(2018). National geographic almanac 2019: Hot new science, incredible photographs, maps, facts, infographics & more (U.S. edition.). National Geographic.
Цитирование в стиле Чикаго (17-е изд.)National Geographic Almanac 2019: Hot New Science, Incredible Photographs, Maps, Facts, Infographics & More. U.S. edition. Washington, D.C.: National Geographic, 2018.
Цитирование MLA (8-е изд.)National Geographic Almanac 2019: Hot New Science, Incredible Photographs, Maps, Facts, Infographics & More. U.S. edition. National Geographic, 2018.
Предупреждение: эти цитированмия не могут быть всегда правильны на 100%.